Fix Neo4jOperator templated query validation

[fat-catTW]

Fix Neo4jOperator so templated Cypher queries are validated after template rendering instead of during operator construction.

This also removes Neo4jOperator from the operator init validator exemption list.

related: #70296

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[shahar1]

Nice!

[github-actions]

Backport failed to create: v3-3-test. View the failure log Run details

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the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

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Status	Branch	Result
❌	v3-3-test

You can attempt to backport this manually by running:

cherry_picker 80e7e9b v3-3-test

This should apply the commit to the v3-3-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.